Pancreatic transplantation in the rat. Long-term study following different methods of management of exocrine drainage.

ABSTRACT

A major problem in pancreas transplantation is the management of exocrine drainage. Isotransplantation has been performed in streptozotocin-induced diabetic rats using a microsurgical technique, and four methods of exocrine drainage have been compared over a nine-month period. The duct system was ligated, left open to drain into the peritoneal cavity, or obliterated with latex or with Ethibloc I occlusion gel. Biochemical follow-up included determinations of serum glucose concentration, intravenous and oral glucose tolerance tests (GTTs), and insulin assays. Histological studies were performed at 1 and 9 months posttransplant. All animals became normoglycemic after the operation. Although 25 out of 28 remained normoglycemic throughout the period of study, oral GTTs performed at six months indicated impaired endocrine function in some of the ligated, freely draining, and Ethibloc I-obliterated animals. Latex-obliterated grafts showed normal oral GTTs up to 9 months postoperatively. Intravenous GTTs showed impairment of endocrine function in all groups, but this was least evident in the latex-obliterated rats. These changes were supported by the peak serum insulin levels during the GTTs. Histologically, long-term ligated, freely draining, and Ethibloc I-obliterated pancreas grafts showed similar degrees of exocrine degeneration, fibrosis, and disruption of islets of Langerhans. In contrast, long term latex-obliterated pancreas grafts demonstrated minimal exocrine tissue and intact islets.